Bobby Flay's Secret Ingredient Jus For The Perfect French Dip Sandwich

Celebrity chef and restaurateur Bobby Flay may be best known for Southwestern food and his grilling mastery, but even he sometimes just wants a classic down-home dish, like a French dip sandwich. "I'm a sucker for, like, good American comfort food," Flay admitted on an episode of the Food Network's "Beat Bobby Flay." While that may be true, he's not above elevating his French dip sandwich with a secret ingredient that might surprise you.

It's porcini mushrooms and he adds them to the jus — typically the drippings left over from roasting the beef — which is used for dipping the steak and cheese on French bread sandwich in. 

The French dip may sound like it comes from overseas, but it's actually as American as you can get. It was allegedly invented by a Los Angeles chef, Philippe Mathieu, more than 100 years ago when he accidentally dropped a French bread roll in a roasting pan full of beef drippings. In Flay's version, instead of beef drippings, he uses beef broth, dried porcini mushrooms, garlic, onion, and rosemary in his jus. He said the porcini mushrooms could be his "secret weapon." 

Many vegetarians know this cooking tip: add porcini mushrooms to meatless dishes for an umami flavor and meatiness. And the same idea goes for the jus Bobby Flay's sandwich is dipped in. For his French dip recipe, the addition of porcini mushrooms imparts an earthiness to the dish. "They'll just elevate the flavor of the beef," Flay said. Porcini mushrooms have an especially rich flavor, which complements the beef broth and helps deepen its savoriness.

These mushrooms that grow wild in pine forests have a special place in French and Italian cooking, especially in risottos and stews, and so they make perfect sense in a beef jus. Flay uses dried porcini mushrooms for this dish, which impart an even deeper mushroom flavor over the fresh variety. After the jus has cooked down, Flay throws it into a blender and then strains out the solids. "I think it has enough porcini flavor," he said. "I don't want to punch more flavor into it."

Besides porcini mushrooms, Bobby Flay has some other tips for a delicious French dip sandwich, from the condiments to add, to the cut of meat he uses. Flay ups the game by foregoing the typical beef cut of chuck or rump roast for tenderloin, which he crusts in a saute pan and finishes in the oven. Besides the porcini jus, Flay includes two different condiments: a mayonnaise with whole grain mustard and horseradish, and a poached garlic butter.

He finishes this elevated French dip by toasting the bread, spreading the mayo on one side and the garlic butter on the other, quickly broiling a nutty gruyere cheese over the sliced beef, and then plating. Besides Flay's tricks for taking your French dip to the next level, there are even more tips for the perfect steak sandwich, from choosing the right bread to perfectly layering your sandwich. 

While Flay's French dip packs quite the flavor punch, it's the porcini jus that truly sets this sandwich apart from the competition. We recommend serving it with Bobby Flay's potato salad which he dresses with bacon, mustard, vinegar, and olive oil. "This is a little short on elegance, and really about satisfaction," Flay said of his French dip. We'll take satisfaction over elegance any day.